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Deiser S, Fenzl S, König V, Drexler M, Smith LM, George ME, Beck R, Witney TH, Inoue S, Casini A. (SiFA)SeFe: A Hydrophilic Silicon-Based Fluoride Acceptor Enabling Versatile Peptidic Radiohybrid Tracers. J Med Chem 2024; 67:14077-14094. [PMID: 39115131 PMCID: PMC11345769 DOI: 10.1021/acs.jmedchem.4c00924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/23/2024]
Abstract
The radiohybrid (rh) concept to design targeted (and chemically identical) radiotracers for imaging or radionuclide therapy of tumors has gained momentum. For this strategy, a new bifunctional Silicon-based Fluoride Acceptor (SiFA) moiety (SiFA)SeFe was synthesized, endowed with improved hydrophilicity and high versatility of integration into rh-compounds. Preliminary radiolabeling and stability studies under different conditions were conducted using model bioconjugate peptides. Further, three somatostatin receptor 2 (sstR2)-targeted rh-compounds ((SiFA)SeFe-rhTATE1-3, TATE = (Tyr3)-octreotate) were developed. Compound (SiFA)SeFe-rhTATE3, enables labeling with 18F for PET imaging or chelation of 177Lu for therapy. The rh-compounds possess comparable receptor binding affinity and in vitro performance as good as the clinically proven gold standards. SstR2-specificity was further shown for (SiFA)SeFe-rhTATE2 using the chicken chorioallantoic membrane (CAM) model. The biodistribution of two compounds in mice showed high accumulation in tumors and excretion via the kidneys, demonstrating the clinical applicability of the (SiFA)SeFe moiety.
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Affiliation(s)
- Sandra Deiser
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Sebastian Fenzl
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
- Institute
of Silicon Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Victor König
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Marike Drexler
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Lydia M. Smith
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Madeleine E. George
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Roswitha Beck
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Timothy H. Witney
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Shigeyoshi Inoue
- Institute
of Silicon Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Angela Casini
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
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2
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Ebner R, Lohse A, Fabritius MP, Rübenthaler J, Wängler C, Wängler B, Schirrmacher R, Völter F, Schmid HP, Unterrainer LM, Öcal O, Hinterberger A, Spitzweg C, Auernhammer CJ, Geyer T, Ricke J, Bartenstein P, Holzgreve A, Grawe F. Validation of the standardization framework SSTR-RADS 1.0 for neuroendocrine tumors using the novel SSTR‑targeting peptide [ 18F]SiTATE. Eur Radiol 2024:10.1007/s00330-024-10788-3. [PMID: 38769164 DOI: 10.1007/s00330-024-10788-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/27/2024] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
OBJECTIVES Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. METHODS Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). RESULTS The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%). CONCLUSION SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1. CLINICAL RELEVANCE STATEMENT SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET. KEY POINTS SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT.
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Affiliation(s)
- R Ebner
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany.
| | - A Lohse
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - M P Fabritius
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - J Rübenthaler
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM, ENETS certified Center of Excellence), LMU University Hospital, LMU Munich, Munich, Germany
| | - C Wängler
- Biomedical Chemistry, Clinic of Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - B Wängler
- Biomedical Chemistry, Clinic of Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
- Molecular Imaging and Radiochemistry, Clinic of Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - R Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, Canada
| | - F Völter
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - H P Schmid
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - L M Unterrainer
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - O Öcal
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - A Hinterberger
- DKFZ Hector Cancer Institute at the University Medical Center Mannheim, Heidelberg, Germany
| | - C Spitzweg
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM, ENETS certified Center of Excellence), LMU University Hospital, LMU Munich, Munich, Germany
- Department of Medicine IV, LMU University Hospital, LMU Munich, Munich, Germany
| | - C J Auernhammer
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM, ENETS certified Center of Excellence), LMU University Hospital, LMU Munich, Munich, Germany
- Department of Medicine IV, LMU University Hospital, LMU Munich, Munich, Germany
| | - T Geyer
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - J Ricke
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM, ENETS certified Center of Excellence), LMU University Hospital, LMU Munich, Munich, Germany
| | - P Bartenstein
- Interdisciplinary Center of Neuroendocrine Tumors of the GastroEnteroPancreatic System (GEPNET-KUM, ENETS certified Center of Excellence), LMU University Hospital, LMU Munich, Munich, Germany
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - A Holzgreve
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - F Grawe
- Department of Radiology, LMU University Hospital, LMU Munich, Munich, Germany
- DKFZ Hector Cancer Institute at the University Medical Center Mannheim, Heidelberg, Germany
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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3
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Gower-Fry L, Wängler C, Bartenstein P, Beyer L, Lindner S, Jurkschat K, Wängler B, Bailey JJ, Schirrmacher R. Silicon-Fluoride Acceptors (SiFA) for 18F-Radiolabeling: From Bench to Bedside. Methods Mol Biol 2024; 2729:29-43. [PMID: 38006489 DOI: 10.1007/978-1-0716-3499-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Fluorine-18 (18F) is undoubtedly one of the most frequently applied radionuclides for the development of new radiotracers for positron emission tomography (PET) in the context of clinical cancer, neurological, and metabolic imaging. Until recently, the available radiochemical methodologies to introduce 18F into organic molecules ranging from small- to medium- and large-sized compounds were limited to a few applicable protocols. With the advent of late-stage fluorination of small aromatic, nonactivated compounds and various noncanonical labeling strategies geared toward the labeling of peptides and proteins, the molecular toolbox for PET radiotracer development was substantially extended. Especially, the noncanonical labeling methodologies characterized by the formation of Si-18F, B-18F, and Al-18F bonds give access to kit-like 18F-labeling of complex and side-group unprotected compounds, some of them already in clinical use. This chapter will particularly focus on silicon-fluoride acceptor (SiFA) chemistry and cover the history of its conceptual design and its translation into the clinical practice.
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Affiliation(s)
- Lexi Gower-Fry
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Dortmund, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Justin J Bailey
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada.
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4
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Ma X, Cheng Z. Rapid Radiolabeling for Peptide Radiotracers. Methods Mol Biol 2024; 2729:103-115. [PMID: 38006493 DOI: 10.1007/978-1-0716-3499-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Peptide-based radiopharmaceuticals (PRPs) have been developed and introduced into research and clinic diagnostic imaging and targeted radionuclide therapy for more than two decades. In order to efficiently prepare PRPs, some rapid radiolabeling methods have been demonstrated. This chapter presents six common approaches for PRPs radiolabeling with metallic radioisotopes and Fluorine-18.
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Affiliation(s)
- Xiaowei Ma
- Department of Nuclear Medicine, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhen Cheng
- State Key Laboratory of Drug Research, Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong, China.
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5
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Deiser S, Drexler M, Moreno-Alcántar G, Irl M, Schmidt C, Günther T, Casini A. Synthesis of 177Lu-Labeled, Somatostatin-2 Receptor-Targeted Metalla-Assemblies: Challenges in the Design of Supramolecular Radiotherapeutics. Inorg Chem 2023; 62:20710-20720. [PMID: 37556427 DOI: 10.1021/acs.inorgchem.3c02090] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Self-assembled supramolecular coordination complexes (SCCs) hold promise for biomedical applications in cancer therapy, although their potential in the field of nuclear medicine is still substantially unexplored. Therefore, in this study an exo-functionalized cationic [Pd2L2]4+ metallacycle (L = 3,5-bis(3-ethynylpyridine)phenyl), targeted to the somatostatin-2 receptor (sst2R) and featuring the DOTA chelator (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) in order to bind the β-- and γ-emitter lutetium-177, was synthesized by self-assembly following ligand synthesis via standard solid-phase peptide synthesis (SPPS). This metallacycle was then characterized by reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry (ESI-MS), and 1H and 1H-DOSY NMR (DOSY = diffusion-ordered spectroscopy). A procedure for the radiolabeling of the metallacycle with 177Lu was also optimized. The resulting [nat/177Lu]Lu-DOTA-metallacycle, termed [nat/177Lu]Lu-Cy, was evaluated concerning its stability and in vitro properties. The compound was more lipophilic compared to the reference [177Lu]Lu-DOTA-TATE (logPOct/H2O = -0.85 ± 0.10 versus -3.67 ± 0.04, respectively). While [natLu]Lu-Cy revealed low stability in a DMEM/F12 GlutaMax medium, it demonstrated good stability in other aqueous media as well as in DMSO. A high sst2R binding affinity (expressed as IC50) was determined in CHOsst2 cells (Chinese hamster ovary cells that were stably transfected with human sst2R). Moreover, the metallacycle exhibited high human serum albumin binding, as assessed by high-performance affinity chromatography (HPAC), and moderate stability in human serum compared to [177Lu]Lu-DOTA-TATE (TATE = (Tyr3)-octreotate). In order to improve stability, a heteroleptic approach was used to develop a less sterically hindered cage-like SCC that is potentially endowed with host-guest chemistry capability, which has been preliminarily characterized by RP-HPLC and ESI-MS. Overall, our initial results encourage future studies on sst2R-directed SCCs and have led to new insights into the chemistry of ss2R-directed SCCs for radiopharmaceutical applications.
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Affiliation(s)
- Sandra Deiser
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Walther-Meißner-Str. 3, 85748 Garching b. München, Germany
- Chair of Medicinal and Bioinorganic Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Marike Drexler
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Walther-Meißner-Str. 3, 85748 Garching b. München, Germany
- Chair of Medicinal and Bioinorganic Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Guillermo Moreno-Alcántar
- Chair of Medicinal and Bioinorganic Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Maximilian Irl
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Walther-Meißner-Str. 3, 85748 Garching b. München, Germany
| | - Claudia Schmidt
- Chair of Medicinal and Bioinorganic Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Thomas Günther
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Walther-Meißner-Str. 3, 85748 Garching b. München, Germany
| | - Angela Casini
- Chair of Medicinal and Bioinorganic Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
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6
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Runacres D, Greenacre VK, Dyke JM, Grigg J, Herbert G, Levason W, McRobbie G, Reid G. Synthesis, Characterization, and Computational Studies on Gallium(III) and Iron(III) Complexes with a Pentadentate Macrocyclic bis-Phosphinate Chelator and Their Investigation As Molecular Scaffolds for 18F Binding. Inorg Chem 2023; 62:20844-20857. [PMID: 38055373 PMCID: PMC10731642 DOI: 10.1021/acs.inorgchem.3c03135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/10/2023] [Accepted: 11/10/2023] [Indexed: 12/08/2023]
Abstract
With the aim of obtaining improved molecular scaffolds for 18F binding to use in PET imaging, gallium(III) and iron(III) complexes with a macrocyclic bis-phosphinate chelator have been synthesized and their properties, including their fluoride binding ability, investigated. Reaction of Bn-tacn (1-benzyl-1,4,7-triazacyclononane) with paraformaldehyde and PhP(OR)2 (R = Me or Et) in refluxing THF, followed by acid hydrolysis, yields the macrocyclic bis(phosphinic acid) derivative, H2(Bn-NODP) (1-benzyl-4,7-phenylphosphinic acid-1,4,7-triazacyclononane), which is isolated as its protonated form, H2(Bn-NODP)·2HCl·4H2O, at low pH (HClaq), its disodium salt, Na2(Bn-NODP)·5H2O at pH 12 (NaOHaq), or the neutral H2(Bn-NODP) under mildly basic conditions (Et3N). A crystal structure of H2(Bn-NODP)·2HCl·H2O confirmed the ligand's identity. The mononuclear [GaCl(Bn-NODP)] complex was prepared by treatment of either the HCl or sodium salt with Ga(NO3)3·9H2O or GaCl3, while treatment of H2(Bn-NODP)·2HCl·4H2O with FeCl3 in aqueous HCl gives [FeCl(Bn-NODP)]. The addition of 1 mol. equiv of aqueous KF to these chloro complexes readily forms the [MF(Bn-NODP)] analogues. Spectroscopic analysis on these complexes confirms pentadentate coordination of the doubly deprotonated (bis-phosphinate) macrocycle via its N3O2 donor set, with the halide ligand completing a distorted octahedral geometry; this is further confirmed through a crystal structure analysis on [GaF(Bn-NODP)]·4H2O. The complex adopts the geometric isomer in which the phosphinate arms are coordinated unsymmetrically (isomer 1) and with the stereochemistry of the three N atoms of the tacn ring in the RRS configuration, denoted (N)RRS, and the phosphinate groups in the RR stereochemistry, denoted (P)RR, (isomer 1/RR), together with its (N)SSR (P)SS enantiomer. The greater thermodynamic stability of isomer 1/RR over the other possible isomers is also indicated by density functional theory (DFT) calculations. Radiofluorination experiments on the [MCl(Bn-NODP)] complexes in partially aqueous MeCN/NaOAcaq (Ga) or EtOH (Ga or Fe; i.e. without buffer) with 18F- target water at 80 °C/10 min lead to high radiochemical incorporation (radiochemical yields 60-80% at 1 mg/mL, or ∼1.5 μM, concentration of the precursor). While the [Fe18F(n-NODP)] is unstable (loss of 18F-) in both H2O/EtOH and PBS/EtOH (PBS = phosphate buffered saline), the [Ga18F(Bn-NODP)] radioproduct shows excellent stability, RCP = 99% at t = 4 h (RCP = radiochemical purity) when formulated in 90%:10% H2O/EtOH and ca. 95% RCP over 4 h when formulated in 90%:10% PBS/EtOH. This indicates that the new "GaIII(Bn-NODP)" moiety is a considerably superior fluoride binding scaffold than the previously reported [Ga18F(Bn-NODA)] (Bn-NODA = 1-benzyl-4,7-dicarboxylate-1,4,7-triazacyclononane), which undergoes rapid and complete hydrolysis in PBS/EtOH (refer to Chem. Eur. J. 2015, 21, 4688-4694).
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Affiliation(s)
- Danielle
E. Runacres
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Victoria K. Greenacre
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - John M. Dyke
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Julian Grigg
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - George Herbert
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - William Levason
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Graeme McRobbie
- GE
HealthCare, Pollards Wood, Nightingales Lane, Chalfont
St. Giles, Buckinghamshire HP8 4SP, United Kingdom
| | - Gillian Reid
- School
of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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7
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Unterrainer M, Kunte SC, Unterrainer LM, Holzgreve A, Delker A, Lindner S, Beyer L, Brendel M, Kunz WG, Winkelmann M, Cyran CC, Ricke J, Jurkschat K, Wängler C, Wängler B, Schirrmacher R, Belka C, Niyazi M, Tonn JC, Bartenstein P, Albert NL. Next-generation PET/CT imaging in meningioma-first clinical experiences using the novel SSTR-targeting peptide [ 18F]SiTATE. Eur J Nucl Med Mol Imaging 2023; 50:3390-3399. [PMID: 37358620 PMCID: PMC10541820 DOI: 10.1007/s00259-023-06315-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 06/17/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Somatostatin-receptor (SSTR)-targeted PET/CT provides important clinical information in addition to standard imaging in meningioma patients. [18F]SiTATE is a novel, 18F-labeled SSTR-targeting peptide with superior imaging properties according to preliminary data. We provide the first [18F]SiTATE PET/CT data of a large cohort of meningioma patients. METHODS Patients with known or suspected meningioma undergoing [18F]SiTATE PET/CT were included. Uptake intensity (SUV) of meningiomas, non-meningioma lesions, and healthy organs were assessed using a 50% isocontour volume of interest (VOI) or a spherical VOI, respectively. Also, trans-osseous extension on PET/CT was assessed. RESULTS A total of 107 patients with 117 [18F]SiTATE PET/CT scans were included. Overall, 231 meningioma lesions and 61 non-meningioma lesions (e.g., post-therapeutic changes) were analyzed. Physiological uptake was lowest in healthy brain tissue, followed by bone marrow, parotid, and pituitary (SUVmean 0.06 ± 0.04 vs. 1.4 ± 0.9 vs. 1.6 ± 1.0 vs. 9.8 ± 4.6; p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6 ± 10.6 vs. 4.0 ± 3.3, p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6±10.6 vs. 4.0±3.3, p<0.001). 93/231 (40.3%) meningiomas showed partial trans-osseous extension and 34/231 (14.7%) predominant intra-osseous extension. 59/231 (25.6%) meningioma lesions found on PET/CT had not been reported on previous standard imaging. CONCLUSION This is the first PET/CT study using an 18F-labeled SSTR-ligand in meningioma patients: [18F]SiTATE provides extraordinary contrast in meningioma compared to healthy tissue and non-meningioma lesions, which leads to a high detection rate of so far unknown meningioma sites and osseous involvement. Having in mind the advantageous logistic features of 18F-labeled compared to 68Ga-labeled compounds (e.g., longer half-life and large-badge production), [18F]SiTATE has the potential to foster a widespread use of SSTR-targeted imaging in neuro-oncology.
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Affiliation(s)
- Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Sophie C Kunte
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Lena M Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Astrid Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Wolfgang G Kunz
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Michael Winkelmann
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Clemens C Cyran
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Jens Ricke
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Dortmund, Germany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Bavarian Cancer Research Center (BZKF), Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Bavarian Cancer Research Center (BZKF), Munich, Germany
| | - Joerg-Christian Tonn
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Bavarian Cancer Research Center (BZKF), Munich, Germany
- Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Bavarian Cancer Research Center (BZKF), Munich, Germany
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8
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Eschbach RS, Hofmann M, Späth L, Sheikh GT, Delker A, Lindner S, Jurkschat K, Wängler C, Wängler B, Schirrmacher R, Tiling R, Brendel M, Wenter V, Dekorsy FJ, Zacherl MJ, Todica A, Ilhan H, Grawe F, Cyran CC, Unterrainer M, Rübenthaler J, Knösel T, Paul T, Boeck S, Westphalen CB, Spitzweg C, Auernhammer CJ, Bartenstein P, Unterrainer LM, Beyer L. Comparison of somatostatin receptor expression in patients with neuroendocrine tumours with and without somatostatin analogue treatment imaged with [ 18F]SiTATE. Front Oncol 2023; 13:992316. [PMID: 36793617 PMCID: PMC9924143 DOI: 10.3389/fonc.2023.992316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 01/09/2023] [Indexed: 01/31/2023] Open
Abstract
Purpose Somatostatin analogues (SSA) are frequently used in the treatment of neuroendocrine tumours. Recently, [18F]SiTATE entered the field of somatostatin receptor (SSR) positron emission tomography (PET)/computed tomography (CT) imaging. The purpose of this study was to compare the SSR-expression of differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET) measured by [18F]SiTATE-PET/CT in patients with and without previous treatment with long-acting SSAs to evaluate if SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT. Methods 77 patients were examined with standardised [18F]SiTATE-PET/CT within clinical routine: 40 patients with long-acting SSAs up to 28 days prior to PET/CT examination and 37 patients without pre-treatment with SSAs. Maximum and mean standardized uptake values (SUVmax and SUVmean) of tumours and metastases (liver, lymphnode, mesenteric/peritoneal and bones) as well as representative background tissues (liver, spleen, adrenal gland, blood pool, small intestine, lung, bone) were measured, SUV ratios (SUVR) were calculated between tumours/metastases and liver, likewise between tumours/metastases and corresponding specific background, and compared between the two groups. Results SUVmean of liver (5.4 ± 1.5 vs. 6.8 ± 1.8) and spleen (17.5 ± 6.8 vs. 36.7 ± 10.3) were significantly lower (p < 0.001) and SUVmean of blood pool (1.7 ± 0.6 vs. 1.3 ± 0.3) was significantly higher (p < 0.001) in patients with SSA pre-treatment compared to patients without. No significant differences between tumour-to-liver and specific tumour-to-background SUVRs were observed between both groups (all p > 0.05). Conclusion In patients previously treated with SSAs, a significantly lower SSR expression ([18F]SiTATE uptake) in normal liver and spleen tissue was observed, as previously reported for 68Ga-labelled SSAs, without significant reduction of tumour-to-background contrast. Therefore, there is no evidence that SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT.
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Affiliation(s)
- Ralf S. Eschbach
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Markus Hofmann
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Lukas Späth
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Gabriel T. Sheikh
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Astrid Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Dortmund, Germany
| | - Carmen Wängler
- Biomedical Chemistry, Clinic of Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Björn Wängler
- Medical Faculty Mannheim of Heidelberg University, Molecular Imaging and Radiochemistry, Clinic of Radiology and Nuclear Medicine, Mannheim, Germany
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Reinhold Tiling
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Vera Wenter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Franziska J. Dekorsy
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Mathias J. Zacherl
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
| | - Freba Grawe
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - Clemens C. Cyran
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - Marcus Unterrainer
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | | | - Thomas Knösel
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Institute of Pathology, LMU, Munich, Germany
| | - Tanja Paul
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Institute of Pathology, LMU, Munich, Germany
| | - Stefan Boeck
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 3, University Hospital, Munich, Germany
| | - Christoph Benedikt Westphalen
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 3, University Hospital, Munich, Germany
| | - Christine Spitzweg
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 4, University Hospital, LMU Munich, Munich, Germany
| | - Christoph J. Auernhammer
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 4, University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
| | - Lena M. Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
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9
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Abstract
18F-Labeling methods for the preparation of 18F-labeled molecular probes can be classified into electrophilic fluorination, nucleophilic fluorination, metal-F coordination, and 18F/19F isotope exchange. Isotope exchange-based 18F-labeling methods demonstrate mild conditions featuring water resistance and facile high-performance liquid chromatography-free purification in direct 18F-labeling of substrates. This paper systematically reviews isotope exchange-based 18F-labeling methods sorted by the adjacent atom bonding with F, i.e., carbon and noncarbon atoms (Si, B, P, S, Ga, Fe, etc.). The respective isotope exchange mechanism, radiolabeling condition, radiochemical yield, molar activity, and stability of the 18F-product are mainly discussed for each isotope exchange-based 18F-labeling method as well as the cutting-edge application of the corresponding 18F-labeled molecular probes.
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Affiliation(s)
- Tao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Shengji Lv
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhaobiao Mou
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhenru Zhang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Taotao Dong
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zijing Li
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Experimental Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
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10
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Zhou L, Long R, Hu M, Liu N, Feng Y, Qiu L, Li Z, Chen Y, Wang L. Synthesis and Evaluation of 18F-Labeled Boramino Acids as Potential New Positron Emission Tomography Agents for Cancer Management. Mol Pharm 2022; 19:2191-2202. [PMID: 35473312 DOI: 10.1021/acs.molpharmaceut.2c00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Boron neutron capture therapy (BNCT) is a promising cancer treatment strategy that utilizes boron-containing ligands. In this report, a series of substituted boramino acids were synthesized and evaluated, aiming to obtain metabolically stable boron-derived agents that could integrate positron emission tomography (PET) with BNCT (a theranostic agent). Based on the phenylalanine (Phe) core structure, the impact of substitution groups on tumor accumulation was studied. The agents were labeled with fluorine-18 in 27.2-66.8% yield via the 18F-19F isotope exchange reaction. In B16-F10 tumor-bearing mice, [18F]-(R)-(1-ammonio-2-(4-methoxyphenyl) ethyl) trifluoroborate (R-[18F]-5a) demonstrated the best tumor uptake (5.54 ± 2.32% ID/g based on ex vivo biodistribution and 3.5 ± 0.04% ID/g based on PET imaging with the tumor-to-muscle ratio up to 2.6) and stability compared with other tested agents. Together, R-[18F]-5a is a promising agent that could potentially integrate PET and BNCT, whose treatment efficacy is worth further evaluation in the future.
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Affiliation(s)
- Liu Zhou
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China.,School of Pharmacy, Southwest Medical University, Luzhou 646608, China
| | - Ruiling Long
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China.,School of Pharmacy, Southwest Medical University, Luzhou 646608, China
| | - Mei Hu
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China.,School of Pharmacy, Southwest Medical University, Luzhou 646608, China
| | - Nan Liu
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China
| | - Yue Feng
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China
| | - Lin Qiu
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China
| | - Zibo Li
- Department of Radiology, Lineberger Comprehensive Cancer Center, and Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Yue Chen
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China
| | - Li Wang
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646099, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan, Luzhou 646099, China.,Academician (Expert) Workstation of Sichuan, Luzhou 646099, China
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11
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Mota F, De Jesus P, Jain SK. Kit-based synthesis of 2-deoxy-2-[ 18F]-fluoro-D-sorbitol for bacterial imaging. Nat Protoc 2021; 16:5274-5286. [PMID: 34686858 PMCID: PMC8611807 DOI: 10.1038/s41596-021-00613-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023]
Abstract
Clinically available imaging tools for diagnosing infections rely on structural changes in the affected tissues. They therefore lack specificity and cannot differentiate between oncologic, inflammatory and infectious processes. We have developed 2-deoxy-2-[18F]fluoro-D-sorbitol (18F-FDS) as an imaging agent to visualize infections caused by Enterobacterales, which represent the largest group of bacterial pathogens in humans and are responsible for severe infections, often resulting in sepsis or death. A clinical study in 26 prospectively enrolled patients demonstrated that 18F-FDS positron emission tomography (PET) was safe, and could detect and localize infections due to drug-susceptible or multi-drug-resistant Enterobacterales strains as well as differentiate them from other pathologies (sterile inflammation or cancer). 18F-FDS is cleared almost exclusively through renal filtration and has also shown potential as a PET agent for functional renal imaging. Since most PET radionuclides have a short half-life, maximal clinical impact will require fast, on-demand synthesis with limited infrastructure and personnel. To meet this demand, we developed a kit-based solid phase method that uses commercially and widely available 2-deoxy-2-[18F]fluoro-D-glucose as the precursor and allows 18F-FDS to be produced and purified in one step at room temperature. The 18F-FDS kit consists of a solid-phase extraction cartridge packed with solid supported borohydride (MP-borohydride), which can be attached to a second cartridge to reduce pH. We evaluated the effects of different solid supported borohydride reagents, cartridge size, starting radioactivity, volumes and flow rates in the radiochemical yield and purity. The optimized protocol can be completed in <30 min and allows the synthesis of 18F-FDS in >70% radiochemical yield and >90% radiochemical purity.
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Affiliation(s)
- Filipa Mota
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Patricia De Jesus
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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12
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Beyer L, Gosewisch A, Lindner S, Völter F, Mittlmeier LM, Tiling R, Brendel M, Cyran CC, Unterrainer M, Rübenthaler J, Auernhammer CJ, Spitzweg C, Böning G, Gildehaus FJ, Jurkschat K, Wängler C, Wängler B, Schirrmacher R, Wenter V, Todica A, Bartenstein P, Ilhan H. Dosimetry and optimal scan time of [ 18F]SiTATE-PET/CT in patients with neuroendocrine tumours. Eur J Nucl Med Mol Imaging 2021; 48:3571-3581. [PMID: 33928401 PMCID: PMC8440281 DOI: 10.1007/s00259-021-05351-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/04/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE Radiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [18F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard 68Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis. METHODS Eight NET patients received a [18F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying 18F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times. RESULTS After 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images. CONCLUSION [18F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to 68Ga-labelled alternatives. For clinical use of [18F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection.
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Affiliation(s)
- Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Friederike Völter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Lena M Mittlmeier
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Reinhold Tiling
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Clemens C Cyran
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - Marcus Unterrainer
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | | | - Christoph J Auernhammer
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 4, University Hospital, LMU Munich, Munich, Germany
| | - Christine Spitzweg
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
- Department of Internal Medicine 4, University Hospital, LMU Munich, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - F J Gildehaus
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Dortmund, Germany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, Alberta, Canada
| | - Vera Wenter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.
- ENETS Centre of Excellence, Interdisciplinary Center of Neuroendocrine Tumours of the GastroEnteroPancreatic System at the University Hospital of Munich (GEPNET-KUM), University Hospital of Munich, Munich, Germany.
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13
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Gower-Fry L, Kronemann T, Dorian A, Pu Y, Jaworski C, Wängler C, Bartenstein P, Beyer L, Lindner S, Jurkschat K, Wängler B, Bailey JJ, Schirrmacher R. Recent Advances in the Clinical Translation of Silicon Fluoride Acceptor (SiFA) 18F-Radiopharmaceuticals. Pharmaceuticals (Basel) 2021; 14:ph14070701. [PMID: 34358127 PMCID: PMC8309031 DOI: 10.3390/ph14070701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/15/2021] [Accepted: 07/17/2021] [Indexed: 12/20/2022] Open
Abstract
The incorporation of silicon fluoride acceptor (SiFA) moieties into a variety of molecules, such as peptides, proteins and biologically relevant small molecules, has improved the generation of 18F-radiopharmaceuticals for medical imaging. The efficient isotopic exchange radiofluorination process, in combination with the enhanced [18F]SiFA in vivo stability, make it a suitable strategy for fluorine-18 incorporation. This review will highlight the clinical applicability of [18F]SiFA-labeled compounds and discuss the significant radiotracers currently in clinical use.
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Affiliation(s)
- Lexi Gower-Fry
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Travis Kronemann
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Andreas Dorian
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Yinglan Pu
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Carolin Jaworski
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany;
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, 44227 Dortmund, Germany;
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany;
| | - Justin J. Bailey
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
- Correspondence:
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14
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Yu Q, Tan X, Li D, Shi B, Wu F, Xu D, Xue W, Wang Z. Automated radiosynthesis of [18F]AlF-NOTA-octreotide and PET/CT imaging in NENs. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07746-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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15
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Sahnoun S, Conen P, Mottaghy FM. The battle on time, money and precision: Da[ 18F] id vs. [ 68Ga]liath. Eur J Nucl Med Mol Imaging 2021; 47:2944-2946. [PMID: 32715336 PMCID: PMC7680323 DOI: 10.1007/s00259-020-04961-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Sabri Sahnoun
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Pauwelsstr. 31, 52074, Aachen, Germany
| | - Patrick Conen
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Pauwelsstr. 31, 52074, Aachen, Germany
| | - Felix M Mottaghy
- Department of Nuclear Medicine, University Hospital RWTH Aachen University, Pauwelsstr. 31, 52074, Aachen, Germany. .,Center of Integrated Oncology (CIO), Universities of Aachen, Bonn, Cologne, and Duesseldorf, Cologne, Germany. .,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debeylaan 25, 6229 HX Maastricht, P.O. Box 5800, 6202 AZ, Maastricht, Netherlands.
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16
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Hübner R, Cheng X, Wängler B, Wängler C. Functional Hybrid Molecules for the Visualization of Cancer: PESIN-Homodimers Combined with Multimodal Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging: Suited for Tracking of GRPR-Positive Malignant Tissue*. Chemistry 2020; 26:16349-16356. [PMID: 32618007 PMCID: PMC7756681 DOI: 10.1002/chem.202002386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Indexed: 12/16/2022]
Abstract
We describe multimodal imaging probes for gastrin-releasing peptide receptor (GRPR)-specific targeting suited for positron emission tomography and optical imaging (PET/OI), consisting of PESIN (PEG3 -BBN7-14 ) dimers connected to multimodal imaging subunits. These multimodal agents comprise a fluorescent dye for OI and the chelator ((1,4,7-triazacyclononane-4,7-diyl)diacetic acid-1-glutaric acid) (NODA-GA) for PET radiometal isotope labelling. Special focus was put on the influence of the used dyes on the properties of the whole bioconjugates. For this, several compounds with different fluorescent dyes and non-dye carrying subunits were synthesized and investigated. As fluorescent dyes, dansyl, NBD, derivatives of fluorescein, coumarin and rhodamine as well as three pyrilium-based dyes were employed. Considerable influence of the charge of the colored unit on hydrophilicity as well as in vitro target receptor binding was observed and classified. High radiochemical yields and purities were found during radiolabeling of the multimodal imaging subunits as well as their GRPR-specific bioconjugates with 68 Ga. Examinations of the photophysical properties of both molecule species displayed no loss or alteration of fluorescence characteristics.
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Affiliation(s)
- Ralph Hübner
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg UniversityTheodor-Kutzer-Ufer 1–368167MannheimGermany
| | - Xia Cheng
- Molecular Imaging and RadiochemistryDepartment of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg UniversityTheodor-Kutzer-Ufer 1–368167MannheimGermany
| | - Björn Wängler
- Molecular Imaging and RadiochemistryDepartment of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg UniversityTheodor-Kutzer-Ufer 1–368167MannheimGermany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg UniversityTheodor-Kutzer-Ufer 1–368167MannheimGermany
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17
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Methods to radiolabel somatostatin analogs with [18F]fluoride: current status, challenges, and progress in clinical applications. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Zhuang H, Guo Z, Zhuang R, Zhang X. Synthesis of 18 F-radiolabeled organophosphine fluorides for thiol-chemoselective peptide conjugation. J Labelled Comp Radiopharm 2020; 63:597-607. [PMID: 32949414 DOI: 10.1002/jlcr.3882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 11/06/2022]
Abstract
Two 18 F-radiolabeled organofluorophosphine fluorides ([18 F]4 and [18 F]7) for chemoselective thiol-conjugation were designed and synthesized via 18 F-19 F isotopic exchange reaction. This simple and rapid radiofluorination produced both 18 F-radiolabeled fluorides in excellent radiochemical yields (>94%) and radiochemical purity. The optimal reaction conditions are 0.05-mg substrate, 0.69 mg of potassium carbonate, and dried [18 F]F- were mixed in 100-μl anhydrous acetonitrile at room temperature for 5 min. Both of [18 F]4 and [18 F]7 showed specificity for thiol-conjugation with cysteine and have been used in the radiosynthesis of c (RGDfC). The [18 F]7 with an adamantanyl-hindered substituent displayed superior in vitro and in vivo stability.
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Affiliation(s)
- Huanglan Zhuang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, China
| | - Zhide Guo
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, China
| | - Rongqiang Zhuang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, China
| | - Xianzhong Zhang
- School of Public Health, Xiamen University, Xiamen, Fujian, China
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19
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Lindner S, Wängler C, Bailey JJ, Jurkschat K, Bartenstein P, Wängler B, Schirrmacher R. Radiosynthesis of [18F]SiFAlin-TATE for clinical neuroendocrine tumor positron emission tomography. Nat Protoc 2020; 15:3827-3843. [DOI: 10.1038/s41596-020-00407-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 09/08/2020] [Indexed: 12/13/2022]
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20
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Wurzer A, Di Carlo D, Schmidt A, Beck R, Eiber M, Schwaiger M, Wester HJ. Radiohybrid Ligands: A Novel Tracer Concept Exemplified by 18F- or 68Ga-Labeled rhPSMA Inhibitors. J Nucl Med 2020; 61:735-742. [PMID: 31862804 PMCID: PMC7198388 DOI: 10.2967/jnumed.119.234922] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/27/2019] [Indexed: 11/16/2022] Open
Abstract
When we critically assess the reason for the current dominance of 68Ga-labeled peptides and peptide-like ligands in radiopharmacy and nuclear medicine, we have to conclude that the major advantage of such radiopharmaceuticals is the apparent lack of suitable 18F-labeling technologies with proven clinical relevance. To prepare and to subsequently perform a clinical proof-of-concept study on the general suitability of silicon-fluoride-acceptor (SiFA)-conjugated radiopharmaceuticals, we developed inhibitors of the prostate-specific membrane antigen (PSMA) that are labeled by isotopic exchange (IE). To compensate for the pronounced lipophilicity of the SiFA unit, we used metal chelates, conjugated in close proximity to SiFA. Six different radiohybrid PSMA ligands (rhPSMA ligands) were evaluated and compared with the commonly used 18F-PSMA inhibitors 18F-DCFPyL and 18F-PSMA-1007. Methods: All inhibitors were synthesized by solid-phase peptide synthesis. Human serum albumin binding was measured by affinity high-performance liquid chromatography, whereas the lipophilicity of each tracer was determined by the n-octanol/buffer method. In vitro studies (IC50, internalization) were performed on LNCaP cells. Biodistribution studies were conducted on LNCaP tumor-bearing male CB-17 SCID mice. Results: On the laboratory scale (starting activities, 0.2-9.0 GBq), labeling of 18F-rhPSMA-5 to -10 by IE was completed in < 20 min (radiochemical yields, 58% ± 9%; radiochemical purity, >97%) with molar activities of 12-60 GBq/μmol. All rhPSMAs showed low nanomolar affinity and high internalization by PSMA-expressing cells when compared with the reference radiopharmaceuticals, medium-to-low lipophilicity, and high human serum albumin binding. Biodistribution studies in LNCaP tumor-bearing mice revealed high tumor uptake, sufficiently fast clearance kinetics from blood, low hepatobiliary excretion, fast renal excretion, and very low uptake of 18F activity in bone. Conclusion: The novel 18F-rhPSMA radiopharmaceuticals developed under the radiohybrid concept show equal or better targeting characteristics than the established 18F-PSMA tracers 18F-DCFPyL and 18F-PSMA-1007. The unparalleled simplicity of production, the possibility to produce the identical 68Ga-labeled 19F-68Ga-rhPSMA tracers, and the possibility to extend this concept to true theranostic radiohybrid radiopharmaceuticals, such as F-Lu-rhPSMA, are unique features of these radiopharmaceuticals.
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Affiliation(s)
- Alexander Wurzer
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Daniel Di Carlo
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Alexander Schmidt
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Roswitha Beck
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Markus Schwaiger
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
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21
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Evaluation of Organo [ 18F]Fluorosilicon Tetrazine as a Prosthetic Group for the Synthesis of PET Radiotracers. Molecules 2020; 25:molecules25051208. [PMID: 32156020 PMCID: PMC7179430 DOI: 10.3390/molecules25051208] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 01/09/2023] Open
Abstract
Fluorine-18 is the most widely used positron emission tomography (PET) radionuclide currently in clinical application, due to its optimal nuclear properties. The synthesis of 18F-labeled radiotracers often requires harsh reaction conditions, limiting the use of sensitive bio- and macromolecules as precursors for direct radiolabeling with fluorine-18. We aimed to develop a milder and efficient in vitro and in vivo labeling method for trans-cyclooctene (TCO) functionalized proteins, through the bioorthogonal inverse-electron demand Diels-Alder (IEDDA) reaction with fluorine-18 radiolabeled tetrazine ([18F]SiFA-Tz). Here, we used TCO-modified bovine serum albumin (BSA) as the model protein, and isotopic exchange (IE) (19F/18F) chemistry as the labeling strategy. The radiolabeling of albumin-TCO with [18F]SiFA-Tz ([18F]6), providing [18F]fluoroalbumin ([18F]10) in high radiochemical yield (99.1 ± 0.2%, n = 3) and a molar activity (MA) of 1.1 GBq/µmol, confirmed the applicability of [18F]6 as a quick in vitro fluorination reagent for the TCO functionalized proteins. While the biological evaluation of [18F]6 demonstrated defluorination in vivo, limiting the utility for pretargeted applications, the in vivo stability of the radiotracer was dramatically improved when [18F]6 was used for the radiolabeling of albumin-TCO ([18F]10) in vitro, prior to administration. Due to the detected defluorination in vivo, structural optimization of the prosthetic group for improved stability is needed before further biological studies and application of pretargeted PET imaging.
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22
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Biodistribution and first clinical results of 18F-SiFAlin-TATE PET: a novel 18F-labeled somatostatin analog for imaging of neuroendocrine tumors. Eur J Nucl Med Mol Imaging 2019; 47:870-880. [DOI: 10.1007/s00259-019-04501-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/21/2019] [Indexed: 12/19/2022]
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23
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Al 18F-NOTA-octreotide and 18F-SiFAlin-TATE: two 'new kids on the block' in somatostatin receptor imaging. Eur J Nucl Med Mol Imaging 2019; 46:2225-2227. [PMID: 31392370 DOI: 10.1007/s00259-019-04474-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 10/26/2022]
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24
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Enzymatically Catalyzed Radiofluorination of Biomolecules. Methods Mol Biol 2019. [PMID: 31332755 DOI: 10.1007/978-1-4939-9654-4_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
There has been significant and rapid growth in the development of amino acid-based molecular imaging agents (e.g., peptides, proteins, and antibody constructs) largely due to facile library preparation and high throughput screening. Positron-emitting fluorine-18 (half-life = 109.7 min) has a unique set of properties that match well with the pharmacokinetics of smaller sized constructs. Several indirect fluorine-18 labeling approaches have been developed yet only a few have advanced to human trials. Enzymatically catalyzed radiofluorination utilizing lipoic acid ligase shows promise as a mild site-specific method for coupling fluorine-18-labeled carboxylate substrates with biomolecules. Methods for preparation of two [18F]fluorocarboxylates and their ligation to a specific peptide sequence (LAP peptide) are presented herein.
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25
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Blower PJ, Levason W, Luthra SK, McRobbie G, Monzittu FM, Mules TO, Reid G, Subhan MN. Exploring transition metal fluoride chelates - synthesis, properties and prospects towards potential PET probes. Dalton Trans 2019; 48:6767-6776. [PMID: 31017131 DOI: 10.1039/c8dt03696a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The coordination chemistry of the first row transition metal trifluorides with terpy (2,2':6',2''-terpyridine) and Me3-tacn (1,4,7-trimethyl-1,4,7-triazacyclononane) was explored to identify potential systems for 18F radiolabelling. The complexes [MF3(L)] (M = Cr, Mn, Fe, Co; L = Me3-tacn, terpy) were synthesised and fully characterised by UV-vis and IR spectroscopy, microanalysis, and, for the diamagnetic [CoF3(L)], using 1H, 19F{1H} and 59Co NMR spectroscopy. Single crystal X-ray analyses are reported for [MF3(Me3-tacn)] (M = Mn, Co), [FeF3(terpy)] and [FeF3(BnMe2-tacn)]. Stability tests on [MF3(Me3-tacn)] (M = Cr, Mn, Fe) and [M'F3(terpy)] (M' = Cr, Fe) were performed and Cl/19F halide exchange reactions on [CrCl3(Me3-tacn)] using [Me4N]F in anhydrous MeCN solution, and [FeCl3(Me3-tacn)] using [Me4N]F in anhydrous MeCN or KF in aqueous MeCN solution were also carried out. Halide exchange reactions proved to be successful in forming [FeF3(Me3-tacn)] in aqueous MeCN solution within 30 minutes. Based upon the clean Cl/F exchange and the good stability observed for [FeF3(Me3-tacn)] in a range of competitive media, this was identified as a possible candidate for radiolabelling. 18F/19F isotopic exchange was achieved by addition of [18F]F- in the cyclotron target water to a MeCN solution of the benzyl-substituted analogue, [FeF3(BnMe2-tacn)], at a range of concentrations down to 24 nM with heating to 80 °C for 10 min.; the resulting [Fe18F19F2(BnMe2-tacn)] shows radiochemical purity (RCP) ≥90% after 2 h in a range of formulations, including 10% EtOH/phosphate buffered saline (PBS) and 10% EtOH/human serum albumin (HSA). This is the first reported complex with a transition metal directly bonded to [18F]F-.
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Affiliation(s)
- Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, London SE1 7EH, UK
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26
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Waldmann CM, Stuparu AD, van Dam RM, Slavik R. The Search for an Alternative to [ 68Ga]Ga-DOTA-TATE in Neuroendocrine Tumor Theranostics: Current State of 18F-labeled Somatostatin Analog Development. Theranostics 2019; 9:1336-1347. [PMID: 30867834 PMCID: PMC6401503 DOI: 10.7150/thno.31806] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/14/2019] [Indexed: 02/06/2023] Open
Abstract
The trend to inform personalized molecular radiotherapy with molecular imaging diagnostics, a concept referred to as theranostics, has transformed the field of nuclear medicine in recent years. The development of theranostic pairs comprising somatostatin receptor (SSTR)-targeting nuclear imaging probes and therapeutic agents for the treatment of patients with neuroendocrine tumors (NETs) has been a driving force behind this development. With the Neuroendocrine Tumor Therapy (NETTER-1) phase 3 trial reporting encouraging results in the treatment of well-differentiated, metastatic midgut NETs, peptide radioligand therapy (RLT) with the 177Lu-labeled somatostatin analog (SSA) [177Lu]Lu-DOTA-TATE is now anticipated to become the standard of care. On the diagnostics side, the field is currently dominated by 68Ga-labeled SSAs for the molecular imaging of NETs with positron emission tomography-computed tomography (PET/CT). PET/CT imaging with SSAs such as [68Ga]Ga-DOTA-TATE, [68Ga]Ga-DOTA-TOC, and [68Ga]Ga-DOTA-NOC allows for NET staging with high accuracy and is used to qualify patients for RLT. Driven by the demand for PET/CT imaging of NETs, a commercial kit for the production of [68Ga]Ga-DOTA-TATE (NETSPOT) was approved by the U.S. Food and Drug Administration (FDA). The synthesis of 68Ga-labeled SSAs from a 68Ge/68Ga-generator is straightforward and allows for a decentralized production, but there are economic and logistic difficulties associated with these approaches that warrant the search for a viable, generator-independent alternative. The clinical introduction of an 18F-labeled SSTR-imaging probe can help mitigate the shortcomings of the generator-based synthesis approach, but despite extensive research efforts, none of the proposed 18F-labeled SSAs has been translated past prospective first-in-humans studies so far. Here, we review the current state of probe-development from a translational viewpoint and make a case for a clinically viable, 18F-labeled alternative to the current standard [68Ga]Ga-DOTA-TATE.
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Affiliation(s)
- Christopher M. Waldmann
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Andreea D. Stuparu
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - R. Michael van Dam
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Roger Slavik
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
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27
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Illert P, Wängler B, Wängler C, Zöllner F, Uhrig T, Litau S, Pretze M, Röder T. Functionalizable composite nanoparticles as a dual magnetic resonance imaging/computed tomography contrast agent for medical imaging. J Appl Polym Sci 2019. [DOI: 10.1002/app.47571] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Patrick Illert
- Institute of Chemical Process EngineeringMannheim University of Applied Sciences Paul‐Wittsack‐Street 10, 68163 Mannheim Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Frank Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Tanja Uhrig
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Shanna Litau
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Marc Pretze
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear MedicineMedical Faculty Mannheim of Heidelberg University Theodor‐Kutzer‐Ufer 1‐3, 68167 Mannheim Germany
| | - Thorsten Röder
- Institute of Chemical Process EngineeringMannheim University of Applied Sciences Paul‐Wittsack‐Street 10, 68163 Mannheim Germany
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28
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Dialer LO, Jodal A, Schibli R, Ametamey SM, Béhé M. Radiosynthesis and evaluation of an 18F-labeled silicon containing exendin-4 peptide as a PET probe for imaging insulinoma. EJNMMI Radiopharm Chem 2018; 3:1. [PMID: 29503858 PMCID: PMC5824708 DOI: 10.1186/s41181-017-0036-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/14/2017] [Indexed: 12/05/2022] Open
Abstract
Background Analogues of exendin-4 have been radiolabeled for imaging the glucagon-like peptide type 1 receptors (GLP-1R) which are overexpressed in insulinoma. The aim of this research was to synthesize an 18F–labeled silicon containing exendin-4 peptide (18F-2) and to evaluate its in vitro and in vivo behavior in CHL-GLP-1 receptor positive tumor-bearing mice. 18F–labeled silicon containing exendin-4 peptide (18F-2) was prepared via one-step nucleophilic substitution of a silane precursor with 18F–fluoride in the presence of acetic acid and K222. 18F-2 was then administered to tumor-bearing mice for PET imaging and ex vivo biodistribution experiments. Results 18F-2 was produced in a radiochemical yield (decay corrected) of 1.5% and a molar activity of max. 16 GBq/μmol. The GLP-1R positive tumors were clearly visualized by PET imaging. Biodistribution studies showed reduced uptake of 18F-2 in the kidneys compared to radiometal labeled exendin-4 derivatives. The radiotracer showed specific tumour uptake which remained steady over 2 h. Conclusions This exendin-4 analogue, 18F-2, is a potential probe for imaging GLP-1R positive tumors.
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Affiliation(s)
- Lukas O Dialer
- 1Center for Radiopharmaceutical Sciences (CRS) of ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Hönggerberg, ETH Zurich, Zurich, Switzerland
| | - Andreas Jodal
- 2Center for Radiopharmaceutical Sciences (CRS), Research Department Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Roger Schibli
- 1Center for Radiopharmaceutical Sciences (CRS) of ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Hönggerberg, ETH Zurich, Zurich, Switzerland.,2Center for Radiopharmaceutical Sciences (CRS), Research Department Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Simon M Ametamey
- 1Center for Radiopharmaceutical Sciences (CRS) of ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Hönggerberg, ETH Zurich, Zurich, Switzerland
| | - Martin Béhé
- 2Center for Radiopharmaceutical Sciences (CRS), Research Department Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
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29
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Bernard-Gauthier V, Lepage ML, Waengler B, Bailey JJ, Liang SH, Perrin DM, Vasdev N, Schirrmacher R. Recent Advances in 18F Radiochemistry: A Focus on B- 18F, Si- 18F, Al- 18F, and C- 18F Radiofluorination via Spirocyclic Iodonium Ylides. J Nucl Med 2017; 59:568-572. [PMID: 29284673 DOI: 10.2967/jnumed.117.197095] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/24/2017] [Indexed: 12/29/2022] Open
Abstract
Straightforward radiosynthesis protocols for 18F-labeled radiopharmaceuticals are an indispensable but often overlooked prerequisite to successfully perform molecular imaging studies in vivo by PET. In recent years, thanks to the expansion of the 18F chemical toolbox, structurally diverse and novel clinically relevant radiopharmaceuticals have been synthesized with both high efficiency and ready implementation. This article provides an overview of recent 18F-labeling methodologies, specifically for B-18F, Si-18F, Al-18F, and iodine (III)-mediated radiofluorination via the spirocyclic iodonium ylide technology.
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Affiliation(s)
- Vadim Bernard-Gauthier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Mathieu L Lepage
- Chemistry Department, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bjoern Waengler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; and
| | - Justin J Bailey
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, Alberta, Canada
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - David M Perrin
- Chemistry Department, University of British Columbia, Vancouver, British Columbia, Canada
| | - Neil Vasdev
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital and Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, Alberta, Canada
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Berke S, Kampmann AL, Wuest M, Bailey JJ, Glowacki B, Wuest F, Jurkschat K, Weberskirch R, Schirrmacher R. 18F-Radiolabeling and In Vivo Analysis of SiFA-Derivatized Polymeric Core–Shell Nanoparticles. Bioconjug Chem 2017; 29:89-95. [DOI: 10.1021/acs.bioconjchem.7b00630] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sheldon Berke
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
| | - Anne-Larissa Kampmann
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
| | - Melinda Wuest
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
| | - Justin J. Bailey
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
| | | | - Frank Wuest
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
| | | | | | - Ralf Schirrmacher
- Department
of Oncology, University of Alberta, 6820 116 Street, Edmonton, Alberta T6G 2R3, Canada
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Jackson IM, Scott PJ, Thompson S. Clinical Applications of Radiolabeled Peptides for PET. Semin Nucl Med 2017; 47:493-523. [DOI: 10.1053/j.semnuclmed.2017.05.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Charron CL, Hickey JL, Nsiama TK, Cruickshank DR, Turnbull WL, Luyt LG. Molecular imaging probes derived from natural peptides. Nat Prod Rep 2017; 33:761-800. [PMID: 26911790 DOI: 10.1039/c5np00083a] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: up to the end of 2015.Peptides are naturally occurring compounds that play an important role in all living systems and are responsible for a range of essential functions. Peptide receptors have been implicated in disease states such as oncology, metabolic disorders and cardiovascular disease. Therefore, natural peptides have been exploited as diagnostic and therapeutic agents due to the unique target specificity for their endogenous receptors. This review discusses a variety of natural peptides highlighting their discovery, endogenous receptors, as well as their derivatization to create molecular imaging agents, with an emphasis on the design of radiolabelled peptides. This review also highlights methods for discovering new and novel peptides when knowledge of specific targets and endogenous ligands are not available.
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Affiliation(s)
- C L Charron
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - J L Hickey
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - T K Nsiama
- London Regional Cancer Program, Lawson Health Research Institute, London, Canada
| | - D R Cruickshank
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - W L Turnbull
- Department of Chemistry, The University of Western Ontario, London, Canada.
| | - L G Luyt
- Department of Chemistry, The University of Western Ontario, London, Canada. and Departments of Oncology and Medical Imaging, The University of Western Ontario, London, Canada and London Regional Cancer Program, Lawson Health Research Institute, London, Canada
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Maschauer S, Heilmann M, Wängler C, Schirrmacher R, Prante O. Radiosynthesis and Preclinical Evaluation of 18F-Fluoroglycosylated Octreotate for Somatostatin Receptor Imaging. Bioconjug Chem 2016; 27:2707-2714. [PMID: 27715017 DOI: 10.1021/acs.bioconjchem.6b00472] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Short synthetic octapeptide analogs derived from the native somatostatin peptides SST-14 and SST-28, namely, octreotate (TATE) or octreotide (TOC), bind with high affinity to somatostatin receptors (sstr), mainly to subtypes 2 and 5, which are expressed in high density on neuroendocrine tumors (NET). Therefore, radiolabeled TATE or TOC derivatives represent highly valuable imaging probes for NET diagnosis by positron emission tomography (PET). The aim of our study was the development of an 18F-labeled octreotate analog as an alternative radiotracer for the clinically established 68Ga-DOTATOC and 68Ga-DOTATATE. We applied our previously developed method based on copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) to the radiosynthesis of 18F-fluoroglycosylated TATE ([18F]FGlc-TATE). [18F]FGlc-TATE was obtained in high yields of 19-22% (non-decay-corrected, referred to [18F]fluoride) and in high specific activities of 32-106 GBq/μmol. [18F]FGlc-TATE showed high affinity to sstr expressed on AR42J cells (IC50 = 4.2 nM) with fast and high internalization, and a beneficial logD7.4 of -1.8. In AR42J tumor bearing nude mice, [18F]FGlc-TATE showed high and specific tumor uptake of 5.6%ID/g at 60 min post-injection, as determined by blocking experiments using octreotide, and fast clearance from other organs, resulting in excellent tumor-to-blood ratios increasing from 9 to 17 from 30 to 60 min post-injection. Small animal PET studies revealed high uptake of [18F]FGlc-TATE in the tumor which could be blocked with octreotide by >99%. Overall, [18F]FGlc-TATE revealed excellent in vitro and in vivo properties and is therefore a viable alternative 18F-labeled radiopeptide for imaging somatostatin receptor-positive tumors by PET.
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Affiliation(s)
- Simone Maschauer
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University Erlangen-Nürnberg (FAU) , Schwabachanlage 6, 91054 Erlangen, Germany
| | - Marcus Heilmann
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University Erlangen-Nürnberg (FAU) , Schwabachanlage 6, 91054 Erlangen, Germany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine Medical Faculty Mannheim of Heidelberg University , Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Ralf Schirrmacher
- Medical Isotope Cyclotron Facility, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Olaf Prante
- Molecular Imaging and Radiochemistry, Department of Nuclear Medicine, Friedrich Alexander University Erlangen-Nürnberg (FAU) , Schwabachanlage 6, 91054 Erlangen, Germany
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Charron CL, Farnsworth AL, Roselt PD, Hicks RJ, Hutton CA. Recent developments in radiolabelled peptides for PET imaging of cancer. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.07.083] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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35
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Poschenrieder A, Osl T, Schottelius M, Hoffmann F, Wirtz M, Schwaiger M, Wester HJ. First 18F-Labeled Pentixafor-Based Imaging Agent for PET Imaging of CXCR4 Expression In Vivo. ACTA ACUST UNITED AC 2016; 2:85-93. [PMID: 30042959 PMCID: PMC6024415 DOI: 10.18383/j.tom.2016.00130] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In vivo quantification of CXCR4 expression using [68Ga]pentixafor for positron emission tomography (PET) imaging has gained significant clinical interest as CXCR4 plays a fundamental role in oncology and possesses potential prognostic value when overexpressed. To combine the excellent CXCR4-targeting properties of pentixafor-based tracers with the favorable radionuclide properties of 18F for high-resolution PET imaging, we developed an Al18F-labeled 1,4,7-triazacyclononane-triacetic acid (NOTA) analog of pentixather. Al18F-labeling of NOTA-pentixather was performed in aqueous dimethyl sulfoxide (DMSO) at pH = 4 (105°C, 15 minutes). CXCR4 affinities were determined in competitive binding assays, and both biodistribution and small-animal PET studies were performed in Daudi lymphoma-bearing mice. Under non-optimized conditions, [18F]AlF-NOTA-pentixather was obtained in radiochemical yields of 45.5% ± 13.3% and specific activities of up to 24.8 GBq/μmol. Compared with [natGa]pentixafor, [natF]AlF-NOTA-pentixather showed 1.4-fold higher CXCR4 affinity. [18F]AlF-NOTA-pentixather displayed high and CXCR4-specific in vivo uptake in Daudi xenografts (13.9% ± 0.8% injected dose per gram [ID/g] at 1 hour post injection [p.i.]). Because of its enhanced lipophilicity (logP = -1.4), [18F]AlF-NOTA-pentixather showed increased accumulation in the gall bladder and intestines. However, tumor/background ratios of 7.0 ± 1.2, 2.0 ± 0.3, 2.2 ± 0.4, 16.5 ± 6.5, and 29.2 ± 4 for blood, liver, small intestine, gut, and muscle, respectively, allowed for high-contrast visualization of Daudi tumors using PET (1 hour p.i.). The relatively straightforward radiosynthesis and efficient CXCR4 targeting of [18F]AlF-NOTA-pentixather demonstrate the successful implementation of 18F-complexation chemistry and pentixather-based CXCR4 targeting. Upon pharmacokinetic optimization, this class of tracers holds great promise for future application in humans.
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Affiliation(s)
| | - Theresa Osl
- Pharmaceutical Radiochemistry, Technische Universität München, Germany and
| | | | - Frauke Hoffmann
- Pharmaceutical Radiochemistry, Technische Universität München, Germany and
| | - Martina Wirtz
- Pharmaceutical Radiochemistry, Technische Universität München, Germany and
| | - Markus Schwaiger
- Nuklearmedizinische Klinik und Poliklinik, Technische Universität München, Ismaningerstr, München, Germany
| | - Hans-Jürgen Wester
- Pharmaceutical Radiochemistry, Technische Universität München, Germany and
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36
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Zhu J, Li S, Wängler C, Wängler B, Lennox RB, Schirrmacher R. Synthesis of 3-chloro-6-((4-(di-tert-butyl[(18)F]fluorosilyl)-benzyl)oxy)-1,2,4,5-tetrazine ([(18)F]SiFA-OTz) for rapid tetrazine-based (18)F-radiolabeling. Chem Commun (Camb) 2016; 51:12415-8. [PMID: 26145162 DOI: 10.1039/c5cc03623b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
An efficient method to prepare the (18)F-labeled tetrazine-derivative [(18)F]-SiFA-OTz for bioorthogonal radiochemistry was developed. [(18)F]-SiFA-OTz can be synthesized with a radiochemical yield of 78 ± 5% within 25 min and can quantitatively react with a model strained dienophile, trans-cyclooctenol.
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Affiliation(s)
- Jun Zhu
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 2K6, Canada.
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Bernard-Gauthier V, Bailey JJ, Liu Z, Wängler B, Wängler C, Jurkschat K, Perrin DM, Schirrmacher R. From Unorthodox to Established: The Current Status of (18)F-Trifluoroborate- and (18)F-SiFA-Based Radiopharmaceuticals in PET Nuclear Imaging. Bioconjug Chem 2015; 27:267-79. [PMID: 26566577 DOI: 10.1021/acs.bioconjchem.5b00560] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Unorthodox (18)F-labeling strategies not employing the formation of a carbon-(18)F bond are seldom found in radiochemistry. Historically, the formation of a boron- or silicon-(18)F bond has been introduced very early on into the repertoire of labeling chemistries, but is without translation into any clinical radiotracer besides inorganic B[(18)F]F4(-) for brain tumor diagnosis. For many decades these labeling methodologies were forgotten and have just recently been revived by a handful of researchers thinking outside the box. When breaking with established paradigms such as the inability to obtain labeled compounds of high specific activity via isotopic exchange or performing radiofluorination in aqueous media, the research community often reacts skeptically. In 2005 and 2006, two novel labeling methodologies were introduced into radiochemistry for positron emission tomography (PET) tracer development: RBF3(-) labeling reported by Perrin et al. and the SiFA methodology by Schirrmacher, Jurkschat, and Waengler et al. which is based on isotopic exchange (IE). Both labeling methodologies have been complemented by other noncanonical strategies to introduce (18)F into biomolecules of diagnostic importance, thus profoundly enriching the landscape of (18)F radiolabeling. B- and Si-based labeling strategies finally revealed that IE is a viable alternative to established and traditional radiochemistry with the advantage of simplifying both the labeling effort as well as the necessary purification of the radiotracer. Hence IE will be the focus of this contribution over other noncanonical labeling methods. Peptides for tumor imaging especially lend themselves favorably toward one-step labeling via IE, but small molecules have been described as well, taking advantage of these new approaches, and have been used successfully for brain imaging. This Review gives an account of both radiochemistries centered on boron and silicon, describing the very beginnings of their basic research, the path that led to optimization of their chemistries, and the first encouraging preclinical results paving the way to their clinical use. This side by side approach will give the reader the opportunity to follow the development of a new basic discovery into a clinically applicable radiotracer including all the hurdles that have had to be overcome.
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Affiliation(s)
- Vadim Bernard-Gauthier
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Justin J Bailey
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Zhibo Liu
- Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health , 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | | | - Klaus Jurkschat
- Department of Chemistry and Chemical Biology, Technical University of Dortmund , 44227 Dortmund, Germany
| | - David M Perrin
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ralf Schirrmacher
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
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Chansaenpak K, Vabre B, Gabbaï FP. [(18)F]-Group 13 fluoride derivatives as radiotracers for positron emission tomography. Chem Soc Rev 2015; 45:954-71. [PMID: 26548467 DOI: 10.1039/c5cs00687b] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The field of (18)F chemistry is rapidly expanding because of the use of this radionuclide in radiotracers for positron emission tomography (PET). Until recently, most [(18)F]-radiotracers were generated by the direct attachment of (18)F to a carbon in the organic backbone of the radiotracer. The past decade has witnessed the emergence of a new strategy based on the formation of an (18)F-group 13 element bond. This approach, which is rooted in the field of fluoride anion complexation/coordination chemistry, has led to the development of a remarkable family of boron, aluminium and gallium [(18)F]-fluoride anion complexing agents which can be conjugated with peptides and small molecules to generate disease specific PET radiotracers. This review is dedicated to the chemistry of these group 13 [(18)F]-fluorides anion complexing agents and their use in PET. Some of the key fluoride-binding motifs covered in this review include the trifluoroborate unit bound to neutral or cationic electron deficient backbones, the BF2 unit of BODIPY dyes, and AlF or GaF3 units coordinated to multidentate Lewis basic ligands. In addition to describing how these moieties can be converted into their [(18)F]-analogs, this review also dicusses their incorporation into bioconjugates for application in PET.
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Affiliation(s)
- Kantapat Chansaenpak
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
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Litau S, Niedermoser S, Vogler N, Roscher M, Schirrmacher R, Fricker G, Wängler B, Wängler C. Next Generation of SiFAlin-Based TATE Derivatives for PET Imaging of SSTR-Positive Tumors: Influence of Molecular Design on In Vitro SSTR Binding and In Vivo Pharmacokinetics. Bioconjug Chem 2015; 26:2350-9. [PMID: 26420336 DOI: 10.1021/acs.bioconjchem.5b00510] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Silicon-Fluoride-Acceptor (SiFA)-(18)F-labeling strategy has been shown before to enable the straightforward and efficient (18)F-labeling of complex biologically active substances such as proteins and peptides. Especially in the case of peptides, the radiolabeling proceeds kit-like in short reaction times and without the need of complex product workup. SiFA-derivatized, (18)F-labeled Tyr(3)-octreotate (TATE) derivatives demonstrated, besides strong somatostatin receptor (SSTR) binding, favorable in vivo pharmacokinetics as well as excellent tumor visualization by PET imaging. In this study, we intended to determine the influence of the underlying molecular design and used molecular scaffolds of SiFAlin-TATE derivatives on SSTR binding as well as on the in vivo pharmacokinetics of the resulting (18)F-labeled peptides. For this purpose, new SiFAlin-(Asp)n-PEG1-TATE analogs (where n = 1-4) were synthesized, efficiently radiolabeled with (18)F in a kit-like manner and obtained in radiochemical yields of 70-80%, radiochemical purities of ≥97%, and nonoptimized specific activities of 20.1-45.2 GBq/μmol within 20-25 min starting from 0.7-1.5 GBq of (18)F. In the following, the radiotracer's lipophilicities and stabilities in human serum were determined. Furthermore, the SSTR-specific binding affinities were evaluated by a competitive displacement assay on SSTR-positive AR42J cells. The obtained in vitro results support the assumption that aspartic acids are able to considerably increase the radiotracer's hydrophilicity and that their number does not affect the SSTR binding potential of the TATE derivatives. The most promising tracer (18)F-SiFAlin-Asp3-PEG1-TATE [(18)F]6 (LogD = -1.23 ± 0.03, IC50 = 20.7 ± 2.5 nM) was further evaluated in vivo in AR42J tumor-bearing nude mice via PET/CT imaging against the clinical gold standard (68)Ga-DOTATATE as well as the previously developed SiFAlin-TATE derivative [(18)F]3. The results of these evaluations showed that [(18)F]6-although showing very similar chemical and in vitro properties to [(18)F]3-exhibits not only a slowed renal clearance compared to [(18)F]3, but also a higher absolute tumor uptake compared to (68)Ga-DOTATATE, and furthermore enables excellent tumor visualization with high image resolution. These results emphasize the importance of systematic study of the influence of molecular design and applied structure elements of peptidic radiotracers, as these may considerably influence in vivo pharmacokinetics while not affecting other parameters such as radiochemistry, lipophilicity, serum stability, or receptor binding potential.
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Affiliation(s)
| | | | | | | | - R Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta , Edmonton T6G 2R3, Canada
| | - G Fricker
- Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg , 69117 Heidelberg, Germany
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40
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Bacher L, Fischer G, Litau S, Schirrmacher R, Wängler B, Baller M, Wängler C. Improving the stability of peptidic radiotracers by the introduction of artificial scaffolds: which structure element is most useful? J Labelled Comp Radiopharm 2015. [PMID: 26219022 DOI: 10.1002/jlcr.3315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Peptidic radiotracers are highly potent substances for the specific in vivo imaging of various biological targets with Single Photon Emission Computed Tomography and Positron Emission Tomography. However, some radiolabeled peptides such as bombesin analogs were shown to exhibit only a limited stability, hampering a successful target visualization. One option to positively influence the stability of radiolabeled peptides is the introduction of certain artificial molecular scaffolds. In order to comparatively assess the influence of different structure elements on the stability of radiolabeled peptides and to identify those structure elements being most useful for peptide radiotracer stabilization, several monomeric and dimeric bombesin derivatives were synthesized, exhibiting differing molecular designs and the chelator NODAGA for (68) Ga-labeling. The radiolabeled peptides were evaluated regarding their in vitro stability in human serum to determine the influence of the introduced molecular scaffolds on the peptides' serum stabilities. The results of the evaluations showed that the introduction of scaffold structures and the overall molecular design have a substantial impact on the stabilities of the resulting peptidic radiotracers. But besides some general trends found using certain scaffold structures, the obtained results point to the necessity to empirically assess their influence on stability for each susceptible peptidic radiotracer individually.
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Affiliation(s)
- Lisa Bacher
- University of Applied Sciences, Campus Zweibrücken, Zweibrücken, Germany.,Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Gabriel Fischer
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany.,Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Shanna Litau
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany.,Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Ralf Schirrmacher
- Department of Oncology, Division Oncological Imaging, University of Alberta, Edmonton, Canada
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Marko Baller
- University of Applied Sciences, Campus Zweibrücken, Zweibrücken, Germany
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
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Zeng JL, Wang J, Ma JA. New strategies for rapid (18)F-radiolabeling of biomolecules for radionuclide-based in vivo imaging. Bioconjug Chem 2015; 26:1000-3. [PMID: 25898224 DOI: 10.1021/acs.bioconjchem.5b00180] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The increasing availability of highly active no-carrier-added [(18)F]-fluoride makes its use in radiolabeling biomolecules attractive. By incorporating "fluorophilic" elements (Si, B, and Al) into biomolecules, recent advances offer mild and rapid (18)F-labeling approaches without HPLC purification at the radiosynthetic stage while maintaining sufficient specific activity. In this Topical Review, we will discuss the most recent strides in the field.
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Affiliation(s)
- Jun-Liang Zeng
- †Department of Chemistry, Key Laboratory of Systems Bioengineering (the Ministry of Education), Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Jian Wang
- ‡Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin 300060, P. R. China
| | - Jun-An Ma
- †Department of Chemistry, Key Laboratory of Systems Bioengineering (the Ministry of Education), Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
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Niedermoser S, Chin J, Wängler C, Kostikov A, Bernard-Gauthier V, Vogler N, Soucy JP, McEwan AJ, Schirrmacher R, Wängler B. In Vivo Evaluation of ¹⁸F-SiFAlin-Modified TATE: A Potential Challenge for ⁶⁸Ga-DOTATATE, the Clinical Gold Standard for Somatostatin Receptor Imaging with PET. J Nucl Med 2015; 56:1100-5. [PMID: 25977461 DOI: 10.2967/jnumed.114.149583] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 04/30/2015] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Radiolabeled peptides for tumor imaging with PET that can be produced with kits are currently in the spotlight of radiopharmacy and nuclear medicine. The diagnosis of neuroendocrine tumors in particular has been a prime example for the usefulness of peptides labeled with a variety of different radionuclides. Among those, (68)Ga and (18)F stand out because of the ease of radionuclide introduction (e.g., (68)Ga isotope) or optimal nuclide properties for PET imaging (slightly favoring the (18)F isotope). The in vivo properties of good manufacturing practice-compliant, newly developed kitlike-producible (18)F-SiFA- and (18)F-SiFAlin- (SiFA = silicon-fluoride acceptor) modified TATE derivatives were compared with the current clinical gold standard (68)Ga-DOTATATE for high-quality imaging of somatostatin receptor-bearing tumors. METHODS SiFA- and SiFAlin-derivatized somatostatin analogs were synthesized and radiolabeled using cartridge-based dried (18)F and purified via a C18 cartridge (radiochemical yield 49.8% ± 5.9% within 20-25 min) without high-performance liquid chromatography purification. Tracer lipophilicity and stability in human serum were tested in vitro. Competitive receptor binding affinity studies were performed using AR42J cells. The most promising tracers were evaluated in vivo in an AR42J xenograft mouse model by ex vivo biodistribution and in vivo PET/CT imaging studies for evaluation of their pharmacokinetic profiles, and the results were compared with those of the current clinical gold standard (68)Ga-DOTATATE. RESULTS Synthetically easily accessible (18)F-labeled silicon-fluoride acceptor-modified somatostatin analogs were developed. They exhibited high binding affinities to somatostatin receptor-positive tumor cells (1.88-14.82 nM). The most potent compound demonstrated comparable pharmacokinetics and an even slightly higher absolute tumor accumulation level in ex vivo biodistribution studies as well as higher tumor standardized uptake values in PET/CT imaging than (68)Ga-DOTATATE in vivo. The radioactivity uptake in nontumor tissue was higher than for (68)Ga-DOTATATE. CONCLUSION The introduction of the novel SiFA building block SiFAlin and of hydrophilic auxiliaries enables a favorable in vivo biodistribution profile of the modified TATE peptides, resulting in high tumor-to-background ratios although lower than those observed with (68)Ga-DOTATATE. As further advantage, the SiFA methodology enables a kitlike labeling procedure for (18)F-labeled peptides advantageous for routine clinical application.
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Affiliation(s)
- Sabrina Niedermoser
- Division of Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Joshua Chin
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Carmen Wängler
- Division of Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Alexey Kostikov
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Vadim Bernard-Gauthier
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada Division of Oncological Imaging, Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Nils Vogler
- Division of Nuclear Medicine, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany; and
| | - Jean-Paul Soucy
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada Concordia-PERFORM Centre, Concordia University, Montreal, Canada
| | - Alexander J McEwan
- Division of Oncological Imaging, Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Ralf Schirrmacher
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada Division of Oncological Imaging, Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Björn Wängler
- Division of Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
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Bhalla R, Levason W, Luthra SK, McRobbie G, Sanderson G, Reid G. Radiofluorination of a pre-formed gallium(III) aza-macrocyclic complex: towards next-generation positron emission tomography (PET) imaging agents. Chemistry 2015; 21:4688-94. [PMID: 25652736 PMCID: PMC4515101 DOI: 10.1002/chem.201405812] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Indexed: 12/04/2022]
Abstract
As part of a study to investigate the factors influencing the development of new, more effective metal-complex-based positron emission tomography (PET) imaging agents, the distorted octahedral complex, [GaCl(L)]⋅2 H2O has been prepared by reaction of 1-benzyl-1,4,7-triazacyclononane-4,7-dicarboxylic acid hydrochloride (H2L⋅HCl) with Ga(NO3)3⋅9 H2O, which is a convenient source of Ga(III) for reactions in water. Spectroscopic and crystallographic data for [GaCl(L)]⋅2 H2O are described, together with the crystal structure of [GaCl(L)]⋅MeCN. Fluorination of this complex by Cl(-)/F(-) exchange was achieved in high yield by treatment with KF in water at room temperature over 90 minutes, although the reaction was complete in approximately 30 minutes if heated to 80 °C, giving [GaF(L)]⋅2 H2O in good yield. The same complex was obtained by hydrothermal synthesis from GaF3⋅3 H2O and Li2L, and has been characterised by single-crystal X-ray analysis, IR, (1)H and (19)F{(1)H} NMR spectroscopy and ESI(+) MS. Radiofluorination of the pre-formed [GaCl(L)]⋅2 H2O has been demonstrated on a 210 nanomolar scale in aqueous NaOAc at pH 4 by using carrier-free (18)F(-), leading to 60-70% (18)F-incorporation after heating to 80 °C for 30 minutes. The resulting radioproduct was purified easily by using a solid-phase extraction (SPE) cartridge, leading to 98-99% radiochemical purity. The [Ga(18)F(L)] is stable for at least 90 minutes in 10% EtOH/NaOAc solution at pH 6, but defluorinates over this time scale at pH of approximately 7.5 in phosphate buffered saline (PBS) or human serum albumin (HSA). The subtle role of the Group 13 metal ion and co-ligand donor set in influencing the pH dependence of this system is discussed in the context of developing potential new imaging agents for PET.
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Affiliation(s)
- Rajiv Bhalla
- Centre for Advanced Imaging, University of Queensland BrisbaneQueensland 4072 (Australia)
| | - William Levason
- Chemistry Department, University of SouthamptonHighfield, Southampton, SO17 1BJ (UK)
| | | | | | - George Sanderson
- Chemistry Department, University of SouthamptonHighfield, Southampton, SO17 1BJ (UK)
| | - Gillian Reid
- Chemistry Department, University of SouthamptonHighfield, Southampton, SO17 1BJ (UK)
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¹⁸F-labeled silicon-based fluoride acceptors: potential opportunities for novel positron emitting radiopharmaceuticals. BIOMED RESEARCH INTERNATIONAL 2014; 2014:454503. [PMID: 25157357 PMCID: PMC4135131 DOI: 10.1155/2014/454503] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Over the recent years, radiopharmaceutical chemistry has experienced a wide variety of innovative pushes towards finding both novel and unconventional radiochemical methods to introduce fluorine-18 into radiotracers for positron emission tomography (PET). These "nonclassical" labeling methodologies based on silicon-, boron-, and aluminium-(18)F chemistry deviate from commonplace bonding of an [(18)F]fluorine atom ((18)F) to either an aliphatic or aromatic carbon atom. One method in particular, the silicon-fluoride-acceptor isotopic exchange (SiFA-IE) approach, invalidates a dogma in radiochemistry that has been widely accepted for many years: the inability to obtain radiopharmaceuticals of high specific activity (SA) via simple IE. METHODOLOGY The most advantageous feature of IE labeling in general is that labeling precursor and labeled radiotracer are chemically identical, eliminating the need to separate the radiotracer from its precursor. SiFA-IE chemistry proceeds in dipolar aprotic solvents at room temperature and below, entirely avoiding the formation of radioactive side products during the IE. SCOPE OF REVIEW A great plethora of different SiFA species have been reported in the literature ranging from small prosthetic groups and other compounds of low molecular weight to labeled peptides and most recently affibody molecules. CONCLUSIONS The literature over the last years (from 2006 to 2014) shows unambiguously that SiFA-IE and other silicon-based fluoride acceptor strategies relying on (18)F(-) leaving group substitutions have the potential to become a valuable addition to radiochemistry.
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Rensch C, Lindner S, Salvamoser R, Leidner S, Böld C, Samper V, Taylor D, Baller M, Riese S, Bartenstein P, Wängler C, Wängler B. A solvent resistant lab-on-chip platform for radiochemistry applications. LAB ON A CHIP 2014; 14:2556-2564. [PMID: 24879121 DOI: 10.1039/c4lc00076e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The application of microfluidics to the synthesis of Positron Emission Tomography (PET) tracers has been explored for more than a decade. Microfluidic benefits such as superior temperature control have been successfully applied to PET tracer synthesis. However, the design of a compact microfluidic platform capable of executing a complete PET tracer synthesis workflow while maintaining prospects for commercialization remains a significant challenge. This study uses an integral system design approach to tackle commercialization challenges such as the material to process compatibility with a path towards cost effective lab-on-chip mass manufacturing from the start. It integrates all functional elements required for a simple PET tracer synthesis into one compact radiochemistry platform. For the lab-on-chip this includes the integration of on-chip valves, on-chip solid phase extraction (SPE), on-chip reactors and a reversible fluid interface while maintaining compatibility with all process chemicals, temperatures and chip mass manufacturing techniques. For the radiochemistry device it includes an automated chip-machine interface enabling one-move connection of all valve actuators and fluid connectors. A vial-based reagent supply as well as methods to transfer reagents efficiently from the vials to the chip has been integrated. After validation of all those functional elements, the microfluidic platform was exemplarily employed for the automated synthesis of a Gastrin-releasing peptide receptor (GRP-R) binding the PEGylated Bombesin BN(7-14)-derivative ([(18)F]PESIN) based PET tracer.
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Affiliation(s)
- Christian Rensch
- GE Global Research, Freisinger Landstrasse 50, 85748 Garching bei Munich, Germany.
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Liu Z, Pourghiasian M, Bénard F, Pan J, Lin KS, Perrin DM. Preclinical Evaluation of a High-Affinity 18F-Trifluoroborate Octreotate Derivative for Somatostatin Receptor Imaging. J Nucl Med 2014; 55:1499-505. [DOI: 10.2967/jnumed.114.137836] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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Wängler C, Chowdhury S, Höfner G, Djurova P, Purisima EO, Bartenstein P, Wängler B, Fricker G, Wanner KT, Schirrmacher R. Shuttle-cargo fusion molecules of transport peptides and the hD2/3 receptor antagonist fallypride: a feasible approach to preserve ligand-receptor binding? J Med Chem 2014; 57:4368-81. [PMID: 24779610 DOI: 10.1021/jm5004123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To determine if the conjugation of a small receptor ligand to a peptidic carrier to potentially facilitate transport across the blood-brain barrier (BBB) by "molecular Trojan horse" transcytosis is feasible, we synthesized several transport peptide-fallypride fusion molecules as model systems and determined their binding affinities to the hD2 receptor. Although they were affected by conjugation, the binding affinities were found to be still in the nanomolar range (between 1.5 and 64.2 nM). In addition, homology modeling of the receptor and docking studies for the most potent compounds were performed, elucidating the binding modes of the fusion molecules and the structure elements contributing to the observed high receptor binding. Furthermore, no interaction between the hybrid compounds and P-gp, the main excretory transporter of the BBB, was found. From these results, it can be inferred that the approach to deliver small neuroreceptor ligands across the BBB by transport peptide carriers is feasible.
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Affiliation(s)
- Carmen Wängler
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University , Montreal H3A 2B4, Canada
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Lindner S, Michler C, Leidner S, Rensch C, Wängler C, Schirrmacher R, Bartenstein P, Wängler B. Synthesis and in vitro and in vivo evaluation of SiFA-tagged bombesin and RGD peptides as tumor imaging probes for positron emission tomography. Bioconjug Chem 2014; 25:738-49. [PMID: 24666287 DOI: 10.1021/bc400588e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Gastrin-releasing-peptide (GRP)-receptors and αvβ3-integrins are widely discussed as potential target structures for oncological imaging with positron emission tomography (PET). Favored by the overexpression of receptors on the surface of tumor cells good imaging characteristics can be achieved with highly specific radiolabeled receptor ligands. PEGylated bombesin (PESIN) derivatives as specific GRP receptor ligands and RGD (one-letter codes for arginine-glycine-aspartic acid) peptides as specific αvβ3 binders were synthesized and tagged with a silicon-fluorine-acceptor (SiFA) moiety. The SiFA synthon allows for a fast and highly efficient isotopic exchange reaction at room temperature giving the [(18)F]fluoride labeled peptides in up to 62% radiochemical yields (d.c.) and ≥99% radiochemical purity in a total synthesis time of less than 20 min. Using nanomolar quantities of precursor high specific activities of up to 60 GBq μmol(-1) were obtained. To compensate the high lipophilicity of the SiFA moiety various hydrophilic structure modifications were introduced leading to significantly reduced logD values. Competitive displacement experiments with the PESIN derivatives showed a 32 to 6 nM affinity to the GRP receptor on PC3 cells, and with the RGD peptides a 7 to 3 μM affinity to the αvβ3 integrins on U87MG cells. All derivatives proved to be stable in human plasma over at least 120 min. Small animal PET measurements and biodistribution studies revealed an enhanced and specific accumulation of the RGD peptide (18)F-SiFA-LysMe3-γ-carboxy-d-Glu-RGD (17) in the tumor tissue of U87MG tumor-bearing mice of 5.3% ID/g whereas the PESIN derivatives showed a high liver uptake and only a low accumulation in the tumor tissue of PC3 xenografts. Stability studies with compound 17 provided further information on its metabolism in vivo. These results altogether demonstrate that the reduction of the overall lipophilicity of SiFA tagged RGD peptides is a promising approach for the generation of novel potent (18)F-labeled imaging agents.
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Affiliation(s)
- Simon Lindner
- Department of Nuclear Medicine, University Hospital Munich, Ludwig-Maximilians-University , 81377 Munich, Germany
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Lindner S, Michler C, Wängler B, Bartenstein P, Fischer G, Schirrmacher R, Wängler C. PESIN Multimerization Improves Receptor Avidities and in Vivo Tumor Targeting Properties to GRPR-Overexpressing Tumors. Bioconjug Chem 2014; 25:489-500. [DOI: 10.1021/bc4004662] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Simon Lindner
- Department
of Nuclear Medicine, University Hospital Munich, Ludwig Maximilians-University Munich, 81377 Munich, Germany
| | - Christina Michler
- Department
of Nuclear Medicine, University Hospital Munich, Ludwig Maximilians-University Munich, 81377 Munich, Germany
| | | | - Peter Bartenstein
- Department
of Nuclear Medicine, University Hospital Munich, Ludwig Maximilians-University Munich, 81377 Munich, Germany
| | - Gabriel Fischer
- Department
of Nuclear Medicine, University Hospital Munich, Ludwig Maximilians-University Munich, 81377 Munich, Germany
| | - Ralf Schirrmacher
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Carmen Wängler
- Department
of Nuclear Medicine, University Hospital Munich, Ludwig Maximilians-University Munich, 81377 Munich, Germany
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